INVESTIGADORES
ECHARTE Laura
artículos
Título:
Kernel set in maize hybrids and their inbred lines exposed to stress
Autor/es:
L. ECHARTE; M. TOLLENAAR
Revista:
CROP SCIENCE
Referencias:
Año: 2006 vol. 46 p. 870 - 878
ISSN:
0011-183X
Resumen:
Heterosis for grain yield in maize (Zea mays L.) has been
associated with heterosis for kernel number. The objective of this
study was to elucidate physiological traits underlying the superior
kernel no. establishment in hybrids in comparison with that in their
inbred lines, using the relationship between kernel no. plant21 (KNP)
and plant growth rate during the critical period of approximately 30 d
bracketing silking (PGRS). Experiments were performed at the Arkell
Research Station near Guelph, ON, Canada, during 2003 and 2004.
Maize was grown at three levels of water availability (100, 75, or 60%
of daily transpiration) during a period bracketing silking and at two
plant densities (6 and 10 plants m22) without nutrient limitations to
generate a range of levels of resource availability plant21. Kernel no.
plant21 was greater in the hybrids than in their parental inbred lines at
all levels of resource availability, which was attributable mainly to a
greater kernel set per unit PGRS in the hybrids. Greater kernels set
per unit PGRS in hybrids vs. their inbred lines resulted from one or
more of the following features: (i) low threshold of PGRS for kernel
set, (ii) high kernel set response to PGRS increments at low resource
availability plant21, and (iii) high potential kernel number. Heterosis
for kernel set was associated with heterosis for ear growth rate during
the critical period for kernel set bracketing silking (EGRs) to varying
degrees, and the extent of the association varied with inbred line
hybrid combination and level of resource availability plant21.